In the angry aftermath of the battle over health care, Republicans and “tea party” activists found themselves playing both defense and offense, condemning violent rhetoric and threats coming from their own ranks while accusing victorious Democrats of hyping the danger for political advantage.

Leaders of the tea party movement said Democratic lawmakers and the mainstream media were seizing on isolated, unrepresentative incidents to vilify the movement as a whole. The disparate, grass-roots movement supplied much of the passion opposing the health care overhaul, but the bulk of the coverage of their protests focused on racial and homophobic taunts targeting Democratic lawmakers.

“Liberals and Democrats, with help from their friends in the media, have tried to marginalize the tea party movement,” said Sal Russo, chief strategist for the Tea Party Express.

“First they said [the tea party movement] was AstroTurf, that these weren’t real people. … Then they said it’s just a bunch of crackpots, and they would go out and find the oddest person in the crowd. Now they’re using race,” he said. “But the attempts to vilify this movement is what you’d expect. It’s not going to work with the tea party.”

As new incidents of intimidation and vandalism targeting lawmakers surfaced Thursday, top congressional Democrats and Republicans united in condemning threats to lawmakers and their families, but immediately divided again over who was egging on the extremists.

Fingers were being pointed Thursday as the Senate approved, on a 56-43 vote, the final piece of Mr. Obama’s health care overhaul plan - a package of “fixes” to the measure approved in a raucous House session Sunday night. Three Democrats joined every Senate Republican in opposing the bill, passed under a “reconciliation” process that blocks any chance for a minority filibuster.

House Minority Whip Eric Cantor, Virginia Republican, said that he, like a number of Democratic lawmakers, had received abusive, hate-filled e-mails and telephone messages, but that he had not publicized the incidents in order not to incite already heated passions over the health care fight.

“By ratcheting up the rhetoric, some will only inflame these situations to dangerous levels,” Mr. Cantor said in a brief news conference at which he took no questions. “Enough is enough. It has to stop.”

“Any suggestion that a leader in this body would incite threats or acts against other members is akin to saying that I would endanger myself, my wife or my children,” said Mr. Cantor, who said someone had shot a bullet through his Richmond office earlier this week.

But Rep. Chris Van Hollen, a Maryland Democrat who was one of those singled out by Mr. Cantor, accused GOP leaders of refusing to take responsibility for unacceptable behavior and tactics in the debate.

“This is straight out of the Republicans political playbook of deflecting responsibility and distracting attention away from a serious issue,” Mr. Van Hollen said.

Among the unsettling incidents reported by Democratic and Republican lawmakers since the vote: a fax bearing the image of a noose; numerous profane and racist voice mails; bricks thrown; a gas line cut; and a mysterious white powder mailed to one congressional district office.

But Senate Sergeant at Arms Terry Gainer also told the Associated Press on Thursday that there was “no evidence that annoying, harassing or threatening telephone calls or e-mails are coordinated.”

Tea party partisans say the attacks are efforts by Democrats to marginalize the anti-spending movement just as it is coalescing from a collection of local factions into a major nationwide political force.

Former Republican vice-presidential candidate Sarah Palin on Saturday will join thousands of protesters in Searchlight, Nev., hometown of Senate Majority Leader Harry Reid. From there, a bus tour coordinated by the Tea Party Express will hit 42 cities in 21 days, ending in Washington on Tax Day, April 15.

At what was billed as the first national tea party “convention” in Nashville, Tenn., last month, Mrs. Palin, a former governor of Alaska, issued an early warning that opponents of the movement would try to attack not its message but its legitimacy.

“Opponents of this message seek to marginalize this movement. They want to paint us as ideologically extreme,” given to “outrageous conspiracy theories aimed at our own government and unethical, shameless tactics,” she said.

Tea party activists say they saw evidence of that campaign in the newspaper and cable network coverage of last weekend’s protests, with reporters and commentators attributing the racial and homophobic attacks to members of the tea party movement.

“During the showdown over health care reform, some of the members of the Tea Party took off their masks,” the Chicago Sun Times wrote on Tuesday.

Over the weekend, as the House was preparing to vote, protesters reportedly spat on a black lawmaker and shouted a racial epithet at another. Another protester called openly gay Rep. Barney Frank, Massachusetts Democrat, a “faggot.”

Republicans didn’t do enough to restrain the protesters, Democrats said, and a few were spotted on a Capitol balcony encouraging protesters shouting slogans such as “Kill the bill.”

“I would hope that we would join together jointly in making it very clear that none of us condone this kind of activity,” Mr. Hoyer said on MSNBC on Wednesday. “And when we see it, that we speak out strongly in opposition to it, and I would hope we would do that going forward.”

Tea partiers moved to distance themselves from the racial and homophobic attacks. Organizers of several Florida tea party groups said in a statement that they “stand in stark opposition to any person using derogatory characterizations, threats of violence or disparaging terms toward members of Congress or the president.”

At least 10 reports by congressional Democrats said they were harassed this week after voting for the health care bill. Congressional offices in New York, Arizona and Kansas were vandalized, and several Democrats reported obscenity-laced phone messages.

But Dale Robertson, founder of teaparty.org, said no one knows who might have yelled out racial epithets during the Capitol Hill protest. He said a Democratic lawmaker refused to accompany Capitol Police officers to identify a white man accused of spitting.

“These people could be anybody. I wouldn’t put it past the Democrats to plant somebody there,” Mr. Robertson said. “They’re trying to label the tea party, but I’ve never seen any racial slurs.”

The bus tour that kicks off Saturday in Nevada will wind across the nation. By its end, organizers say, the tour will have drawn hundreds of thousands to its protests. Mrs. Palin, who is solidifying her ties to the group, plans to urge protesters to keep focused - and polite.

“Governor Palin will again share her belief that debate must be civil and peaceful - and that the best place for Americans to express their frustration with Washington, D.C., and their commitment to our founding principles is at the ballot box this November,” said a Palin aide who asked not to be named.